When I join a project,like einstein,BOINC would download lots of files.

What confused me is that the downloading speed is very very low,usually at 1KB/s.

When I suspend the network,then resume,the speed rise,at 100KB/s for 5-10 seconds,and drop again.

I am using 1M ADSL.

Why can't BOINC make full use of my net?

If you didn't set your preferences to anything else than for BOINC to use the maximum, it must be something local. Aren't you also downloading other things at the same time?

Else try to set a maximum download and upload rate in your preferences. These are in KB/sec. For a 1Mbit line, your maximum download speed can be set to 100KB/sec (1024 divided by 8 minus overhead).

If both are left at zero BOINC will use whatever speed it can get from the server. Einstein has pretty fast servers, depending on which mirror you're using. I'm on one of the European servers and getting speeds like this:
17-Jan-09 23:02:00|Einstein@Home|[file_xfer_debug] Throughput 153694 bytes/sec

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